Serial chart - minimize # of categories using expressions?

Question

I am trying to create a serial chart in ArcGIS Dashboard (Enterprise v12) but the unique number of categories is almost 360 and the bar chart is too overwhelming with this many values.  I would like to minimize it by using data expressions but not sure how to do it.  For example, current data is setup like:

TypeDescriptor (additional field - unrelated)Speed Limit: 5mph5Speed Limit: 10mph63Speed Limit: 15mph32Speed Limit: 20mph80Speed Limit: 25mph46Warning: Dead end3Warning: Bicycles10Warning: Pedestrian8Regulatory: Stop79...and so onetc.

I would like to group these in the chart as a single category by "Speed Limit*" so the expression would create a table like this below.  Is this possible?  If so then I could really use the help and greatly appreciate it!

TypeDescriptorNew field for ChartSpeed Limit: 5mph5Speed LimitSpeed Limit: 10mph63Speed LimitSpeed Limit: 15mph32Speed LimitSpeed Limit: 20mph80Speed LimitSpeed Limit: 25mph46Speed LimitWarning: Dead end3WarningWarning: Bicycles10WarningWarning: Pedestrian8WarningRegulatory: Stop79Regulatory...and so onetc.etc.

kenbuja · Accepted Answer

Here's one way to create that new field.

This takes the Schema of your original FeatureSet (line 9) and adds the additional field "Category" (line 10). It creates a dictionary for a new FeatureSet (lines 12-16), then loops through the records in the original Featureset (line 17) and copying all the attributes (lines 20-22). For the new "Category" field, it takes the value from the "Type" attribute, splits it into an array, and extracts the text before the colon (line 23). The attributes are added into a new feature (line 25) and a new FeatureSet is created from the dictionary (line 27).

var fs = FeatureSetByPortalItem(
  Portal("yourPortal"),
  "yourItem",
  0,
  ["*"],
  false
);

for (var attr in f) {
    attrs[attr] = f[attr];
  }
  attrs["Category"] = Split(f["Type"], ":")[0];

Push(temp_dict["features"], { attributes: attrs, geometry: Geometry(f) });
}
return Featureset(temp_dict);

kenbuja · Accepted Answer

This would return the first seven characters

attrs["Category"] = Left(f["Type"], 7);